Method for manufacturing semiconductor device

ABSTRACT

A method of manufacturing a semiconductor device according to one embodiment includes forming a first film including a first metal above a processing target member. The method includes forming a second film including two or more types of element out of a second metal, carbon, and boron above the first film. The method includes forming a third film including the first metal above the second film. The method includes forming a mask film by providing an opening part to a stacked film including the first film, the second film and the third film. The method includes processing the processing target member by performing etching using the mask film as a mask.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromU.S. Provisional Patent Application 62/272,401, filed on Dec. 29, 2015;the entire contents of which are incorporated herein by reference.

FIELD

Embodiments relate to a method for manufacturing a semiconductor device.

BACKGROUND

In recent years, there has been proposed a stacked-type semiconductormemory device having memory cells integrated three-dimensionally. Whenmanufacturing such a stacked-type semiconductor memory device, memoryholes penetrating a stacked body are formed by etching. On thisoccasion, if the number of layers stacked in the stacked body increases,the aspect ratio of the memory hole becomes high, and therefore, a highetching resistance is required for the etching mask.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 through FIG. 9 are cross-sectional views showing a method ofmanufacturing a semiconductor device according to a first embodiment;

FIG. 10 is a cross-sectional view showing the semiconductor deviceaccording to the first embodiment;

FIG. 11 is a cross-sectional view showing an area A of FIG. 10;

FIG. 12 is a perspective view showing the semiconductor device accordingto the first embodiment;

FIG. 13 is a graph chart showing a relationship between a thickness anda stress of a tungsten film with a horizontal axis representing thethickness of the tungsten film and a vertical axis representing thestress of the tungsten film;

FIG. 14 is a schematic cross-sectional view showing a stacked mask filmused in the first embodiment;

FIG. 15 is a cross-sectional view showing a method of manufacturing asemiconductor device according to a first modified example of the firstembodiment;

FIG. 16 is a cross-sectional view showing a semiconductor deviceaccording to a second modified example of the first embodiment;

FIG. 17 is a schematic cross-sectional view showing a stacked mask filmused in a second embodiment;

FIG. 18 is a schematic cross-sectional view showing a stacked mask filmused in a third embodiment;

FIG. 19 is a schematic cross-sectional view showing a stacked mask filmused in a fourth embodiment; and

FIG. 20 is a schematic cross-sectional view showing a stacked mask filmused in a fifth embodiment.

DETAILED DESCRIPTION

A method of manufacturing a semiconductor device according to oneembodiment includes forming a first film including a first metal above aprocessing target member. The method includes forming a second filmincluding two or more types of element out of a second metal, carbon,and boron above the first film. The method includes forming a third filmincluding the first metal above the second film. The method includesforming a mask film by providing an opening part to a stacked filmincluding the first film, the second film and the third film. The methodincludes processing the processing target member by performing etchingusing the mask film as a mask.

First Embodiment

Firstly, a first embodiment will be described.

FIG. 1 through FIG. 9 are cross-sectional views showing a method ofmanufacturing a semiconductor device according to the embodiment.

FIG. 10 is a cross-sectional view showing the semiconductor deviceaccording to the embodiment.

FIG. 11 is a cross-sectional view showing an area A of FIG. 10.

FIG. 12 is a perspective view showing the semiconductor device accordingto the embodiment.

The semiconductor device according to the embodiment is a stacked-typenonvolatile semiconductor memory device.

Firstly, a method of manufacturing the semiconductor device according tothe embodiment will be described.

As shown in FIG. 1, a silicon substrate 10 is prepared. The siliconsubstrate 10 is a part of a silicon wafer. Hereinafter, in thespecification, for the sake of convenience of explanation, there isadopted an XYZ Cartesian coordinate system. Two directions parallel toan upper surface 10 a of the silicon substrate 10, and perpendicular toeach other are defined as an “X-direction” and a “Y-direction,” and adirection perpendicular to the upper surface 10 a of the siliconsubstrate 10 is defined as a “Z-direction.”

Firstly, a silicon oxide film 11 is formed on the silicon substrate 10.It should be noted that in the specification, the “silicon oxide film”denotes a film consisting primarily of a silicon oxide. Therefore, thesilicon oxide film 11 includes silicon (Si) and oxygen (O). Further,since the silicon oxide is generally an insulating material, the siliconoxide film is an insulating film unless particularly explained. The samealso applies to other constituents, and in the case in which the name ofa material is included in the name of a constituent, the principalcomponent of the constituent is the material.

Then, silicon nitride films 12 and silicon oxide films 13 arealternately formed on the silicon oxide film 11. On this occasion, it isarranged that the uppermost layer is the silicon oxide film 13. Thesilicon nitride films 12 are each a sacrifice film to be removed in alater process. The silicon oxide film 11, the plurality of siliconnitride films 12, and the plurality of silicon oxide films 13 constitutethe stacked body 15. It should be noted that in FIG. 1, just six pairseach formed of the silicon nitride film 12 and the silicon oxide film 13are shown for the sake of convenience of graphical description, but thisconfiguration is not a limitation, and several tens of pairs, or severalhundreds of pairs, for example, can be stacked on one another. Thethickness, namely the length in the Z-direction, of the stacked body 15is set to, for example, 2 through 4 μm (micrometers).

Then, a resist mask (not shown) is formed on the stacked body 15. Then,by alternately performing etching using the resist mask as a mask, andsliming of the resist mask, an end part of the stacked body 15 in theY-direction is processed to have a stepped shape. Then, by depositingthe silicon oxide on the entire surface, and then performing aplanarization process such as CMP (Chemical Mechanical Polishing) on theupper surface, an interlayer insulating film (not shown) covering theend part of the stacked body 15 is formed on the silicon substrate 10.

Then, a carbon-containing tungsten film 21 consisting primarily oftungsten (W) and including carbon (C) is formed on the stacked body 15.For example, the carbon-containing tungsten film 21 has contact with thesilicon oxide film 13 constituting the uppermost layer of the stackedbody 15. The carbon concentration in the carbon-containing tungsten film21 is set to such a concentration that a compound (W—C alloy) oftungsten and carbon is formed, but single-phase carbon is notprecipitated, and is set to, for example, 1 atomic percent or higher,and 50 atomic percent or lower.

The carbon-containing tungsten film 21 is formed using, for example, aCVD (Chemical Vapor Deposition) method such as a PECVD (Plasma EnhancedCVD) method. On this occasion, it is possible to use tungstenhexafluoride (WF₆) as a source gas of tungsten, propylene (C₃H₆) as asource gas of carbon, and hydrogen (H₂) as a reducing gas, for example.

As the source gas of tungsten, an inorganic-system gas such as tungstenhexachloride (WCl₆) or tungsten hexacarbonyl (W(CO)₆) can also be used.Alternatively, an organic-system gas can also be used as the source gasof tungsten. As the organic-system gas, there can be used, for example,bis (cyclopentadienyl) tungsten(IV) dihydride (C₁₀H₁₂W),cyclopentadienyltungsten(II) tricarbonyl hydride (C₈H₆O₃W), bis(tert-butylimino) bis (tert-butylamino) tungsten ((C₄H₉NH)₂W(C₄H₉N)₂),tetracarbonyl (1,5-cyclooctadiene) tungsten(0) (C₁₂H₁₂O₄W),triamminetungsten(IV) tricarbonyl ((NH₃)₃W(CO)₃), tungsten(0)pentacarbonyl-N-pentylisonitrile ((CO)₅WCN(CH₂)₄CH₃), bis(isopropylcyclopentadienyl) tungsten(IV) dihydride ((C₅H₄CH(CH₃)₂)₂WH₂),bis (tert-butylimino) bis (dimethylamino) tungsten(VI)(((CH₃)₃CN)₂W(N(CH₃)₂)₂), bis (butylcyclopentadienyl) tungsten(IV)diiodide (C₁₈H₂₆I₂W), or bis (cyclopentadienyl) tungsten(IV) dichloride(C₁₀H₁₀Cl₂W). Further, as the source gas of carbon, there can be usedacetylene (C₂H₂), ethylene (C₂H₄), or methane (CH₄).

Then, a tungsten film 22 made of tungsten is formed on thecarbon-containing tungsten film 21 using, for example, a CVD method suchas a PECVD method. As the source gas of tungsten, there is used the gasdescribed above. The tungsten film 22 is formed to be thicker than thecarbon-containing tungsten film 21. It should be noted that thecarbon-containing tungsten film 21 and the tungsten film 22 can also beformed using a sputtering method. In this case, the carbon-containingfilm 21 and the tungsten film 22 are separately formed by, for example,switching the target.

Thereafter, the carbon-containing tungsten films 21 and the tungstenfilms 22 are alternately formed to form a stacked film 23. For example,in the stacked film 23, the carbon-containing tungsten films 21 and thetungsten films 22 are arranged at intervals along the Z-direction. Thecarbon-containing tungsten films 21 and the tungsten films 22 can alsobe deposited using respective deposition methods different from eachother. However, in order to enhance the productivity, it is preferableto continuously deposit the both films in the same device withoutbreaking a vacuum.

It should be noted that just five pairs each formed of thecarbon-containing tungsten film 21 and the tungsten film 22 are shown inFIG. 1 and FIG. 2 for the sake of convenience of graphical description,but this configuration is not a limitation. In one example, thethickness of each of the carbon-containing tungsten films 21 is set to10 nm (nanometers), the thickness of each of the tungsten films 22 isset to 40 nm, and the ten pairs each formed of the carbon-containingtungsten film 21 and the tungsten film 22 are formed to set the totalthickness of the stacked film 23 to 500 nm. In the tungsten film 22,carbon may inevitably diffuse from the carbon-containing tungsten film21 in some cases, but the carbon concentration in the tungsten film 22is lower than the carbon concentration in the carbon-containing tungstenfilm 21.

The stacked film 23 is not a single-layer tungsten film, but amultilayer film obtained by inserting the carbon-containing tungstenfilms 21 between the respective tungsten films 22. Therefore, comparedto the case of forming a thick single-layer tungsten film, thecompressive stress of the stacked film 23 can be relaxed. Thus, the warpof the silicon wafer due to the formation of the stacked film 23, andexfoliation between the stacked body 15 and the stacked film 23 can beinhibited. In the following description, in some cases, the tungstenfilm 22 is referred to as a “metal film” in a broader concept, and thecarbon-containing tungsten film 21 is referred to as a“stress-decoupling film” in a broader concept.

Then, an amorphous silicon layer 25 a, an antireflection layer 25 b, anda resist layer 25 c are formed on the stacked film 23. Then, theantireflection layer 25 b and the amorphous silicon layer 25 a arepatterned by patterning the resist layer 25 c using a lithographymethod, and then performing etching using the resist layer 25 c as amask. Thus, there is formed a plurality of opening parts 25 h eachpenetrating the resist layer 25 c, the antireflection layer 25 b, andthe amorphous silicon layer 25 a. It is assumed that, when viewed fromthe Z-direction, for example, the opening parts 25 h are arranged in azigzag manner, and the shape of each of the opening parts 25 h is acircular shape. In such a manner, a mask 25 is formed. It should benoted that it is also possible to form an inorganic insulating materiallayer or an organic material layer instead of the amorphous siliconlayer 25 a. Alternatively, it is also possible to form the mask 25 bycombining these layers.

Then, as shown in FIG. 2, by performing anisotropic etching using themask 25, the stacked film 23 is patterned. As the anisotropic etching,there is performed RIE (Reactive Ion Etching) using an etching gasincluding, for example, fluorine and bromine. Thus, opening parts 23 aeach penetrating the stacked film 23 in the Z-direction are provided tothe stacked film 23, and thus, a stacked mask film 23 m is formed. Onthis occasion, if the carbon-containing tungsten film 21 is etched, areaction product including carbon is generated, and adheres to an innersurface of each of the opening parts 23 a. Thus, a protective film 27 isformed on the inner surface of each of the opening parts 23 a.

Then, as shown in FIG. 3, by performing anisotropic etching using thestacked mask film 23 m as a mask, memory holes 26 are provided to thestacked body 15. As the anisotropic etching, there is performed RIEusing an etching gas including, for example, fluorine and carbon. Onthis occasion, although the etching rate is low compared to the stackedbody 15, the stacked mask film 23 m is etched to some extent. When thecarbon-containing tungsten film 21 is etched due to the etching of thestacked body 15, a reaction product including carbon is generated, andadheres to an inner surface of each of the opening parts 23 a. Due alsoto this process, the protective film 27 is formed on the inner surfaceof each of the opening parts 23 a.

When the stacked film 23 m is etched due to the etching of the stackedbody 15, an upper part of the inner surface of each of the opening parts23 a is processed to have a tapered shape flaring upward. However, sincein the embodiment, the protective film 27 is formed on the inner surfaceof each of the opening parts 23 a, the stacked mask film 23 m isprotected from etching, and thus, deformation of the opening parts 23 ais inhibited.

Then, as shown in FIG. 4, in the state in which the memory holes 26reach the silicon substrate 10, the anisotropic etching is stopped.Subsequently, the stacked mask film 23 m is removed together with theprotective films 27 using, for example, a wet process. In such a manner,the memory holes 26 are provided to the stacked body 15.

Then, as shown in FIG. 5, by performing an oxidation treatment, areaswhere the silicon nitride films 12 are exposed in the inner surface ofeach of the memory holes 26 are oxidized to form silicon oxide films 28.Then, a silicon nitride is deposited on the inner surface of each of thememory holes 26 using, for example, a CVD method to form a chargestorage film 31. The charge storage film 31 is a film capable of storingthe charge, and is formed of a material having trap sites of electrons,and is formed of, for example, a silicon nitride as described above.

Then, a silicon oxide, a silicon nitride, and a silicon oxide aredeposited in this order using, for example, a CVD method to form atunnel insulating film 32 on a side surface of the charge storage film31. The tunnel insulating film 32 is a film, which has an insulatingproperty in a normal state, and allows the tunnel current to flow when apredetermined voltage within the range of the drive voltage of thesemiconductor device is applied. The tunnel insulating film 32 can alsobe an ONO film as described above, or can also be a single-layer siliconoxide film.

Then, by depositing silicon on a side surface of the tunnel insulatingfilm 32, a cover silicon layer is formed. Then, the cover silicon layer,the tunnel insulating film 32, and the charge storage film 31 areremoved from a surface of the bottom of each of the memory holes 26using, for example, an RIE method to expose the silicon substrate 10.Then, by depositing the silicon, a silicon body is embedded in each ofthe memory holes 26. The cover silicon layer and the silicon bodyconstitute a silicon pillar 35. It should be noted that it is alsopossible to form a core member made of a silicon oxide by not completelyfilling the memory holes 26 with the silicon body, and then depositingthe silicon oxide.

Then, as shown in FIG. 6, by forming a mask film (not shown) using alithography method, and then performing RIE using the mask film, aplurality of trenches 37 reaching the silicon substrate 10 is formed ina part where the silicon pillar 35 is not formed in the stacked body 15.The trenches 37 extend in the Y-direction, and are terminated in the endpart in the Y-direction of the stacked body 15. Since the end part inthe Y-direction of the stacked body 15 is processed to have a steppedshape, the upper part of the stacked body 15 is divided by the trenches37 in a line-and-space manner, and the lower part of the stacked body 15is not completely divided. Therefore, the shape becomes a comb-likeshape obtained by connecting a plurality of line-shaped parts, each ofwhich is sandwiched by the trenches 37, to each other in the end part inthe Y-direction.

Then, as shown in FIG. 7, wet etching is performed via the trenches 37.The condition of the wet etching is set to the condition in which asilicon nitride is selectively etched with respect to a silicon oxide,and hot phosphoric acid, for example, is used as the etchant. Thus, thesilicon nitride films 12 (see FIG. 6) are removed via the trenches 37 toform spaces 38. On this occasion, the silicon oxide films 11 and 12 arenot substantially etched, and are exposed on the lower surfaces and theupper surfaces of the spaces 38. Further, the silicon oxide films 28 arealso not substantially etched, and each function as an etch stopper forprotecting the charge storage film 31. Then, a small amount of etchingto the silicon oxide is performed to remove the silicon oxide films 28.Thus, the charge storage films 31 are exposed in the spaces 38. Thesilicon pillars 35 surrounded by the charge storage films 31 support thesilicon oxide films 13 and so on to prevent the spaces 38 from gettingcrushed.

Then, as shown in FIG. 8, a silicon oxide and an aluminum oxide aredeposited in this order using, for example, a CVD method. Thus, blockinsulating films 39 are formed on the inner surfaces of the trenches 37and the spaces 38. The block insulating films 39 are each a filmsubstantially preventing a current from flowing even in the case inwhich a voltage is applied within a range of the drive voltage of thesemiconductor device. As described above, the block insulating films 39are each a two-layer film, for example, having a silicon oxide layer 39a (see FIG. 11) and an aluminum oxide layer 39 b (see FIG. 11) stackedon one another. It should be noted that the block insulating film canalso be a three-layer film having a silicon oxide layer, an aluminumoxide layer, and a silicon oxide layer stacked on one another, or canalso be a multilayer film having hafnium oxide layers and silicon oxidelayers stacked on one another, or can also be a single-layer siliconoxide film. For example, an average dielectric constant of the entireblock insulating film 39 is higher than an average dielectric constantof the entire tunnel insulating film 32. The tunnel insulating film 32,the charge storage film 31, and the block insulating film 39 constitutea memory film 40.

Then, a metal nitride such as a titanium nitride, a tantalum nitride, ora tungsten nitride is deposited using, for example, a CVD method. Thus,barrier metal layers 41 are formed on the inner surfaces of the trenches37 and the spaces 38. The barrier metal layers 41 are formed so as notto completely fill in the trenches 37 and the spaces 38.

Then, tungsten is deposited using, for example, a CVD method to fill inthe spaces 38. On this occasion, tungsten is also deposited on the sidesurface of each of the trenches 37. Then, by performing etching, partsdeposited in the trenches 37 out of the block insulating films 39, thebarrier metal layers 41, and tungsten are removed. Thus, tungstenembedded in the spaces 38 is divided into the spaces 38 to form aplurality of electrode films 42 stacked on one another.

Then, as shown in FIG. 9, a silicon oxide is deposited on the innersurface of each of the trenches 37. Then, a part deposited on the bottomsurface of each of the trenches 37 in the silicon oxide is removed.Thus, silicon oxide plates 43 are formed on the respective side surfacesof each of the trenches 37, and at the same time, the silicon substrate10 is exposed on the bottom surface of each of the trenches 37. Then,the trenches 37 are filled with a conductive material such as tungstento form source electrode plates 44.

Then, as shown in FIG. 10 and FIG. 12, a silicon oxide is deposited onthe stacked body 15 to form a silicon oxide film 46. It should be notedthat some of the constituents including the silicon oxide film 46 areomitted in FIG. 12 for the sake of convenience of graphical description.Then, using a lithography method and an RIE method, an opening part isformed in an area immediately above the silicon pillar 35 in the siliconoxide film 46, and then the opening part is filled with a conductivematerial to form a plug 47. The plug 47 is connected to the siliconpillar 35. Then, a source line 48 extending in the X-direction is formedon the silicon oxide film 46, and is connected to the source electrodeplates 44 via plugs (not shown). Further, bit lines 49 each extending inthe X-direction are formed on the silicon oxide film 46, and areconnected to the respective plugs 47. Subsequently, the silicon wafer isdiced into individual segments. In such a manner as described above, thesemiconductor device 1 according to the embodiment is manufactured.

Then, a configuration of the semiconductor device 1 manufactured in sucha manner as described above will be described.

As shown in FIG. 10 and FIG. 12, in the semiconductor device 1 accordingto the embodiment, there is provided the silicon substrate 10. On thesilicon substrate 10, there is provided the stacked body 15. In thestacked body 15, the silicon oxide film 11 is provided as the lowermostlayer, and the electrode films 42 and the silicon oxide films 13 arealternately stacked on the silicon oxide film 11. The electrode films 42are each formed of, for example, tungsten.

In the stacked body 15, there is provided the plurality of sourceelectrode plates 44 each extending in the Y-direction. The lower ends ofthe respective source electrode plates 44 are connected to the siliconsubstrate 10. The source electrode plates 44 each have a plate-likeshape, the longitudinal direction, in which the shape is the longest, isparallel to the Y-direction, the width direction, in which the shape isthe second longest, is parallel to the Z-direction, and the thicknessdirection, in which the shape is the shortest, is parallel to theX-direction. The source electrode plates 44 are each formed of, forexample, tungsten (W). On the side surfaces facing to the both sides inthe X-direction of each of the source electrode plates 44, there areprovided the silicon oxide plates 43 each having a plate-like shape,respectively.

The shape of the end part in the Y-direction of the stacked body 15 isthe stepped shape (not shown) having steps formed for the respectiveelectrode films 42, and the source electrode plates 44 and the siliconoxide plates 43 are terminated in the end part having the stepped shape.Therefore, the shape of the electrode film 42 disposed in the upper partof the stacked body 15 is a line-and-space shape divided by the sourceelectrode plates 44 and the silicon oxide plates 43, and the shape ofthe electrode film 42 disposed in the lower part of the stacked body 15is a comb-like shape.

In the stacked body 15, there are provided the silicon pillars 35 eachextending in the Z-direction. The silicon pillars 35 are each made ofpolysilicon, and each have a columnar shape. The lower end of each ofthe silicon pillars 35 is connected to the silicon substrate 10, and theupper end is exposed on the upper surface of the stacked body 15. Itshould be noted that the silicon pillars 35 can each have a cylindricalshape with the lower end part closed, and a core member made of, forexample, a silicon oxide can also be provided in the cylindrical shape.When viewed from the Z-direction, the silicon pillars 35 are arranged atintervals along two or more lines such as four lines. The lines eachextend in the Y-direction, and between the lines adjacent to each other,the positions of the silicon pillars 35 in the Y-direction are shiftedas much as a half pitch from each other. In the specification, such anarrangement is referred to as a “fourfold hound's-tooth check.”

On the stacked body 15, there is provided the silicon oxide film 46, andin the silicon oxide film 46, there are provided the plugs 47. On thesilicon oxide film 46, there are provided the source line 48 extendingin the X-direction and the plurality of bit lines 49 each extending inthe X-direction. The source electrode plates 44 are connected to thesource line 48 via the plugs (not shown). The silicon pillars 35 areconnected to the bit lines 49 via the plugs 47, respectively. In such amanner, the silicon pillars 35 are connected between the respective bitlines 49 and the silicon substrate 10.

As shown in FIG. 11, on the side surface of each of the silicon pillars35, there is provided the tunnel insulating film 32, and on the sidesurface of the tunnel insulating film 32, there is provided the chargestorage film 31. On the other hand, on each of the upper surface, thelower surface, and the side surfaces facing to the silicon pillars 35 ofeach of the electrode films 42, there are provided the barrier metallayer 41, the aluminum oxide layer 39 b, and the silicon oxide layer 39a. The aluminum oxide layer 39 b and the silicon oxide layer 39 aconstitute the block insulating film 39, and the block insulating film39, the charge storage film 31, and the tunnel insulating film 32constitute the memory film 40. The silicon oxide layer 39 a has contactwith the charge storage film 31.

In the stacked body 15, upper one or more of the electrode films 42divided to have the line-and-space shape each function as an upperselection gate line SGD, and at each of the crossing parts between theupper selection gate lines SGD and the silicon pillars 35, there isformed an upper selection gate transistor STD. Further, among theelectrode films 42 divided to have the comb-like shape, lower one ormore of the electrode films 42 each function as a lower selection gateline SGS, and at each of the crossing parts between the lower selectiongate lines SGS and the silicon pillars 35, there is formed a lowerselection gate transistor STS. The electrode films 42 other than thelower selection gate lines SGS or the upper selection gate lines SGD areeach function as a word line WL, and at each of the crossing partsbetween the word lines WL and the silicon pillars 35, there is formed amemory cell transistor MC. Thus, the memory cell transistors MC areconnected in series to each other along each of the silicon pillars 35,and the lower selection gate transistors STS and the upper selectiongate transistors STD are connected to the respective ends thereof toform a NAND string.

Then, advantages of the embodiment will be described.

In the embodiment, in the process shown in FIG. 3, when forming thememory holes 26 by etching the stacked body 15, the stacked mask film 23m made of metal is used as the etching mask. Since the metal mask ishigh in etching resistance, the stacked mask film 23 m can be formedthinner compared to the case of using a nonmetallic mask. As a result,the stacked mask film 23 m is easy to form, and therefore, thesemiconductor device 1 is easy to manufacture.

However, if the metal etching mask is used, strong stress occurs in theetching mask. Therefore, in the embodiment, as shown in FIG. 2, as theconfiguration of the stacked mask film 23 m, there is adopted amultilayer film obtained by inserting the carbon-containing tungstenfilms 21 between the respective tungsten films 22 instead of thesingle-layer thick tungsten film. Thus, it is possible to relax thecompressive stress of the stacked mask film 23 m while ensuring thesufficient etch resistance. As a result, it is possible to reduce thecompressive stress of the stacked mask film 23 m to inhibit the warp ofthe silicon wafer and the exfoliation of the stacked mask film 23 m.Therefore, the semiconductor device 1 is easy to manufacture.

Hereinafter, the advantage will be described in detail.

FIG. 13 is a graph chart showing a relationship between the thicknessand the stress of the tungsten film with the horizontal axisrepresenting the thickness of the tungsten film and the vertical axisrepresenting the stress of the tungsten film.

FIG. 14 is a schematic cross-sectional view showing the stacked maskfilm used in the embodiment.

As shown in FIG. 13, according to the experimental result of theinventors, there is a roughly linear function-like relationship betweenthe thickness and the stress of the tungsten film, and the thinner thetungsten film is, the stronger the tensile stress becomes, and thethicker the tungsten film is, the stronger the compressive stressbecomes. The reason is presumed that the thinner the tungsten film ismade, the smaller the grain size of the tungsten film becomes, and thus,the increase in compressive stress due to the increase in the grain sizecan be avoided. Further, in the thickness of the tungsten film, thereexists the thickness t₀ at which the stress nearly vanishes. In theexample shown in FIG. 13, the thickness t₀ at which the stress nearlyvanishes exists in a range of 30 through 40 nm.

It should be noted that the relationship between the film thickness andthe stress is different by the type of metal which the film is made of,and the deposition conditions. In the case of forming the film by, forexample, a CVD method, the relationship is affected by the depositiontemperature and the flow ratio of the gas used. In the case of a PECVDmethod, the relationship is also affected by the plasma power. Further,in the case of forming the film by a sputtering method, the relationshipis affected by the temperature, the flow rate of the argon gas, and theDC power. Therefore, by controlling these conditions, the relationshipbetween the film thickness and the stress can be selected. In the caseof, for example, forming the tungsten film by the PECVD method, the morethe DC power is increased, the weaker the compressive stress becomes,even if the film thickness is constant.

For example, if the compressive stress caused in the carbon-containingtungsten films 21 as the stress-decoupling films is made weaker than thecompressive stress caused in the tungsten films 22 as the metal films,it is possible to decoupling the stress of the tungsten films 22 by thecarbon-containing tungsten film 21 to thereby reduce the stress of theentire stacked film 23. Further, if the composition of the film and theconditions are appropriately selected, it is possible to cause thetensile stress in the stress-decoupling films to thereby cancel thecompressive stress caused in the metal films. Thus, the stress of theentire stacked film can further be reduced.

In the embodiment, by setting, for example, the thickness of each of thetungsten films 22 to appropriately 40 nm, and inserting thecarbon-containing tungsten films 21 between the respective tungstenfilms 22, the stress of each of the tungsten films 22 can beapproximated to zero. Further, since the tungsten films 22 are decoupledfrom each other by the carbon-containing tungsten films 21, it ispossible to keep the stress of each of the tungsten films 22 in thenear-zero state to thereby suppress the stress of the entire stackedfilm 23.

In contrast, if the mask film is formed of a thick single-layer tungstenfilm, since the thicker the tungsten film becomes, the stronger thecompressive stress becomes as shown in FIG. 13, strong compressivestress is caused as the entire mask film. Thus, when the mask film hasbeen formed, the silicon wafer largely warps. As a result, it becomesdifficult to adjust the focus of exposure, and thus, the accuracy oflithography is degraded. Further, since the silicon wafer largely warps,handling in the succeeding processes becomes difficult. Further, due tothe compressive stress, the mask film exfoliates in some cases. Asdescribed above, if the mask film is formed of the single-layer metalfilm, excessive compressive stress is caused, and the productivity ofthe semiconductor device drops.

Further, as shown in FIG. 3, when etching the stacked body 15, thestacked mask film 23 m is also etched inevitably. On this occasion,since in the embodiment, the carbon-containing tungsten films 21 areprovided in the stacked mask film 23 m, the carbon-containing tungstenfilms 21 are etched to thereby produce the reactant including carbon.The reactant adheres to the inner surface of each of the opening parts23 a to form the protective film 27 against etching. Thus, the innersurface of each of the opening parts 23 a is inhibited from being etchedto deform to have a tapered shape, and it is possible to keep the shapeof the opening part 23 a in a preferable state until the end of theetching of the stacked body 15. As a result, the memory holes 26 canaccurately be formed. Further, even in the case in which the memoryholes 26 are arranged at short intervals, the deformation of one of theopening parts 23 a can be inhibited from affecting adjacent one of theopening parts 23 a. As a result, the arrangement intervals of the memoryholes 26 can be shortened.

Further, in the embodiment, the principal component of thecarbon-containing tungsten films 21 is tungsten, which is the same asthe principal component of the tungsten films 22. Therefore, the etchingcharacteristics of the carbon-containing tungsten films 21 and theetching characteristics of the tungsten films 22 are similar to eachother, and the stacked film 23 is easy to etch. This also makes thesemiconductor device 1 easy to manufacture.

Furthermore, in the embodiment, the silicon oxide film 13 is disposed asthe uppermost layer of the stacked body 15, and the carbon-containingtungsten film 21 is disposed as the lowermost layer of the stacked film23. Therefore, the adhesiveness between the stacked body 15 and thestacked film 23 is better compared to the case of disposing the tungstenfilm 22 as the lowermost layer of the stacked film 23.

It should be noted that although in the embodiment, there is describedthe example of forming the tungsten films 22 as the metal films, andforming the carbon-containing tungsten films 21 as the stress-decouplingfilms, the example is not a limitation. For example, the metal films canbe formed of one or more types of metal selected from a group consistingof tungsten (W), molybdenum (Mo), tantalum (Ta), cobalt (Co), andtitanium (Ti). Similarly, the stress-decoupling films can be formed ofone of more types of carbon-containing metal selected from a groupconsisting of W—C, Mo—C, Ta—C, Co—C, and Ti—C. In order to make theetching characteristics similar to each other, the metal forming themetal films and the metal to be the principal component of thestress-decoupling films preferably coincide with each other, but are notnecessarily required to coincide with each other. Further, it is alsopossible for the metal films and the stress-decoupling films to includeother components than the metal to be the principal component or carbon.Further, the film thickness of the tungsten films 22 is not limited tothe film thickness t₀.

First Modified Example of First Embodiment

Then, a first modified example of the first embodiment will bedescribed.

FIG. 15 is a cross-sectional view showing a method of manufacturing asemiconductor device according to the modified example.

As shown in FIG. 15, in the modified example, a liner film 20 is formedon the stacked body 15. The liner film 20 has contact with the siliconoxide film 13. The liner film 20 is formed using, for example, a nitrideof the metal constituting the metal films, or a material obtained bymaking the metal include nitrogen. Specifically, in the modifiedexample, since the tungsten films 22 are formed as the metal films, theliner film 20 is formed using a tungsten nitride (WN) ornitrogen-containing tungsten (W—N). It should be noted that in the caseof forming the metal films using molybdenum, tantalum, cobalt, ortitanium, the liner film is formed using a molybdenum nitride (MoN) ornitrogen-containing molybdenum (Mo—N), a tantalum nitride (TaN) ornitrogen-containing tantalum (Ta—N), a cobalt nitride (CoN) ornitrogen-containing cobalt (Co—N), or a titanium nitride (TiN) ornitrogen-containing titanium (Ti—N).

Further, when forming the stacked film 23, the tungsten film 22 isformed first. The tungsten film 22 has contact with the liner film 20.Since the uppermost layer of the stacked film 23 is the tungsten film22, in the modified example, the number of the tungsten films 22 stackedis larger by one than the number of the carbon-containing tungsten films21 stacked.

According to the modified example, by providing the liner film 20between the stacked body 15 and the stacked film 23, the adhesivenessbetween the stacked body 15 and the stacked film 23 can be improved. Asa result, the exfoliation of the stacked mask film 23 m can more surelybe prevented.

Except the points described above, the manufacturing method,configurations, and advantages of the semiconductor device in themodified example are substantially the same as in the first embodimentdescribed above.

Second Modified Example of First Embodiment

Then, a second modified example of the first embodiment will bedescribed.

FIG. 16 is a cross-sectional view showing a semiconductor deviceaccording to the modified example.

FIG. 16 shows a part corresponding to an area A of FIG. 10.

Firstly, the processes shown in FIG. 1 through FIG. 4 are performed.

Then, as shown in FIG. 16, a silicon oxide layer 39 a is formed on theinner surface of each of the memory holes 26. Then, the charge storagefilm 31, the tunnel insulating film 32, and the silicon pillar 35 areformed on the side surface of the silicon oxide layer 39 a usingsubstantially the same method as those in the first embodiment.

Then, the processes shown in FIG. 6 and FIG. 7 are performed.

Then, as shown in FIG. 16, an aluminum oxide layer 39 b is formed on theinner surface of the spaces 38 from which the silicon nitride films 12have been removed.

Then, the processes shown in FIG. 8 through FIG. 10 are performed. Thus,the semiconductor device 1 a according to the modified example can bemanufactured.

In the modified example, out of the block insulating film 39, thesilicon oxide layer 39 a is formed via the memory hole 26, and thealuminum oxide layer 39 b is formed via the slit 37. Thus, since thesilicon oxide layer 39 a becomes not to intervene between the electrodefilms 42 adjacent to each other in the Z-direction, miniaturization inthe Z-direction can be achieved. Further, the process of forming thesilicon oxide film 28 (see FIG. 5) on the inner surface of each of thememory holes 26 can be eliminated.

Except the points described above, the manufacturing method,configurations, and advantages in the modified example are substantiallythe same as in the first embodiment described above.

It should be noted that although in the modified example, there isdescribed the example in which the block insulating film 39 is atwo-layer film formed of the silicon oxide layer 39 a and the aluminumoxide layer 39 b, even in the case in which other film configurationsare adopted, it is possible to form a part of the block insulating filmvia the memory hole 26 and to form the rest of the block insulating filmvia the slit 37.

Second Embodiment

Then, a second embodiment will hereinafter be described.

FIG. 17 is a schematic cross-sectional view showing the stacked maskfilm used in the embodiment.

As shown in FIG. 17, the embodiment is different in the configuration ofthe stacked mask film for forming the memory holes compared to the firstembodiment described above.

Hereinafter, a method of manufacturing the semiconductor deviceaccording to the embodiment will be described.

Firstly, the stacked body 15 is formed on the silicon substrate 10 asshown in FIG. 1, and then the end part in the Y-direction is processedto have the stepped shape.

Then, as shown in FIG. 17, a boron-containing tungsten film 61consisting primarily of tungsten and including boron (B) is formed onthe stacked body 15 (see FIG. 1). The boron concentration in theboron-containing tungsten film 61 is set to such a concentration that acompound (W—B compound) of tungsten and boron is formed, butsingle-phase boron is not precipitated, and is set to, for example, 1atomic percent or higher, and 66 atomic percent or lower.

The boron-containing tungsten film 61 is formed using, for example, aplasma CVD method. On this occasion, as a source gas of boron, there canbe used, for example, diborane (B₂H₆), boron trifluoride (BF₃), orpentaborane (B₅H₉). The source gas and the reducing gas of tungsten arearranged to be substantially the same as those in the first embodimentdescribed above.

Then, the tungsten film 22 made of tungsten is formed on theboron-containing tungsten film 61 using, for example, a plasma CVDmethod. The tungsten film 22 is formed to be thicker than theboron-containing tungsten film 61. It should be noted that theboron-containing tungsten film 61 and the tungsten film 22 can also beformed using a sputtering method. In this case, the boron-containingfilm 61 and the tungsten film 22 are separately formed by, for example,switching the target.

Thereafter, the boron-containing tungsten films 61 and the tungstenfilms 22 are alternately formed to form a stacked film 63. It should benoted that in the tungsten film 22, boron may inevitably diffuse fromthe boron-containing tungsten film 61 in some cases, but the boronconcentration in the tungsten film 22 is lower than the boronconcentration in the boron-containing tungsten film 61.

Then, by forming the mask 25 (see FIG. 1) on the stacked film 63, andthen performing anisotropic etching such as RIE using the mask 25, thestacked film 63 is patterned to form the stacked mask film 63 m. Itshould be noted that just five pairs each formed of the boron-containingtungsten film 61 and the tungsten film 22 are shown in FIG. 17 for thesake of convenience of graphical description, but this configuration isnot a limitation. It is sufficient that, for example, as shown in FIG.13, a preliminary experiment is performed to obtain the film thicknessof the tungsten film at which the stress becomes weak, and then thenumber of the boron-containing tungsten films 61 and the tungsten films22 stacked on one another is determined so that the etch resistancedesired for the stacked mask film 63 m is realized.

The succeeding processes are substantially the same as those of thefirst embodiment described above. Further, the configuration of thesemiconductor device manufactured in the embodiment is substantially thesame as in the first embodiment.

Also in the embodiment, similarly to the first embodiment describedabove, since the stacked mask film 63 m using tungsten as the basematerial is used when forming the memory holes 26, the stacked mask film63 m can be formed thinner compared to the case of using a nonmetallicmask.

Further, in the stacked mask film 63 m, since the boron-containingtungsten films 61 are inserted between the respective tungsten films 22,the compressive stress can be relaxed while ensuring the sufficient etchresistance. As a result, the warp of the silicon wafer and theexfoliation of the stacked mask film 63 m can be suppressed.

Further, in the embodiment, since the boron-containing tungsten films 61are provided in the stacked mask film 63 m, the reactant including boronis produced when the boron-containing tungsten films 61 are etched, andthe protective film is formed on the inner surface of each of theopening parts of the stacked mask film 63 m. Thus, it is possible toinhibit the inner surface of each of the opening parts from being etchedand deformed to have a tapered shape, and thus, the memory holes 26 canaccurately be formed.

Furthermore, in the embodiment, the principal component of theboron-containing tungsten films 61 is tungsten, which is the same as theprincipal component of the tungsten films 22. Therefore, the stackedfilm 63 is easy to etch.

Except the points described above, the manufacturing method and theadvantages of the embodiment are substantially the same as in the firstembodiment described above.

Third Embodiment

Then, a third embodiment will be described.

FIG. 18 is a schematic cross-sectional view showing the stacked maskfilm used in the embodiment.

As shown in FIG. 18, the embodiment is different in the configuration ofthe stacked mask film for forming the memory holes compared to the firstand second embodiments described above.

As shown in FIG. 18, in the embodiment, a carbon-boron-containingtungsten film 71 consisting primarily of tungsten and including boron(B) and carbon (C) is formed on the stacked body 15 (see FIG. 1). Thetotal concentration of carbon and boron in the carbon-boron-containingtungsten film 71 is set to such a concentration that each of carbon andboron forms a compound with tungsten, but single-phase carbon andsingle-phase boron are not precipitated. For example, the carbonconcentration and the boron concentration are each set to 1 atomicpercent or higher. Further, assuming the carbon concentration in thecarbon-boron-containing tungsten film 71 as x atomic percent, and theboron concentration as y atomic percent, the concentrations x and y areset so as to fulfill the following formula.

100≧2x+( 3/2)y

The carbon-boron-containing tungsten film 71 is formed using, forexample, a plasma CVD method. On this occasion, for example, the sourcegas of tungsten, the source gas of carbon, and the reducing gas arearranged to be substantially the same as those in the first embodiment.The source gas of boron is arranged to be substantially the same as thatin the second embodiment.

Then, the tungsten film 22 made of tungsten is formed on thecarbon-boron-containing tungsten film 71 using, for example, a plasmaCVD method. The tungsten film 22 is formed to be thicker than thecarbon-boron-containing tungsten film 71. It should be noted that thecarbon-boron-containing tungsten film 71 and the tungsten film 22 canalso be formed using a sputtering method. In this case, for example, thecarbon-boron-containing tungsten film 71 is formed by performingsputtering using tungsten including carbon and boron (W—B—C) as atarget, and the tungsten film 22 is formed by performing sputteringusing tungsten as a target.

Thereafter, the carbon-boron-containing tungsten films 71 and thetungsten films 22 are alternately formed to form a stacked film 73. Itshould be noted that in the tungsten film 22, carbon and boron mayinevitably diffuse from the carbon-boron-containing tungsten film 71 insome cases, but the total concentration of carbon and boron in thetungsten film 22 is lower than the total concentration of carbon andboron in the carbon-boron-containing tungsten film 71. Then, bypatterning the stacked film 73, the stacked mask film 73 m is formed.

Also in the embodiment, the reactant including carbon and boron isproduced when the carbon-boron-containing tungsten film 71 is etched,and the protective film is formed on the inner surface of each of theopening parts of the stacked mask film 73 m. Thus, the memory holes 26can accurately be formed.

Except the points described above, the manufacturing method,configurations, and advantages of the semiconductor device in theembodiment are substantially the same as in the first embodimentdescribed above.

Fourth Embodiment

Then, a fourth embodiment will be described.

FIG. 19 is a schematic cross-sectional view showing the stacked maskfilm used in the embodiment.

As shown in FIG. 19, the embodiment is different in the configuration ofthe stacked mask film for forming the memory holes compared to the firstthrough third embodiments described above.

As shown in FIG. 19, in the embodiment, a boron carbide film 81consisting primarily of boron carbide (BC) is formed on the stacked body15 (see FIG. 1). The concentration of boron carbide in the boron carbidefilm 81 is arranged to be, for example, 50 atomic percent or higher. Theboron carbide film 81 is formed using, for example, a plasma CVD method.On this occasion, for example, the source gas of carbon and the reducinggas are arranged to be substantially the same as those in the firstembodiment. The source gas of boron is arranged to be substantially thesame as that in the second embodiment. It should be noted that the boroncarbide film 81 can also be formed using a sputtering method.

Then, the tungsten film 22 made of tungsten is formed on the boroncarbide film 81 using, for example, a plasma CVD method. The tungstenfilm 22 is formed to be thicker than the boron carbide film 81.

Thereafter, the boron carbide films 81 and the tungsten films 22 arealternately formed to form a stacked film 83. It should be noted that inthe tungsten film 22, boron and carbon may inevitably diffuse from theboron carbide film 81 in some cases, but the total concentration ofcarbon and boron in the tungsten film 22 is lower than the totalconcentration of carbon and boron in the boron carbide film 81. Further,in the boron carbide film 81, tungsten may inevitably diffuse from thetungsten film 22 in some cases, but the tungsten concentration in theboron carbide film 81 is lower than the tungsten concentration in thetungsten film 22. Then, by patterning the stacked film 83, the stackedmask film 83 m is formed.

Also in the embodiment, the reactant including boron and carbon isproduced when the boron carbide film 81 is etched, and the protectivefilm is formed on the inner surface of each of the opening parts of thestacked mask film 83 m. Thus, the memory holes 26 can accurately beformed.

Further, in the embodiment, since the boron carbide films 81 high inhardness are provided in the stacked mask film 83 m, the etch resistanceof the stacked mask film 83 m is high, and the stacked mask film 83 mcan be formed thinner accordingly.

Except the points described above, the manufacturing method,configurations, and advantages of the semiconductor device in theembodiment are substantially the same as in the first embodimentdescribed above.

Fifth Embodiment

Then, a fifth embodiment will be described.

FIG. 20 is a schematic cross-sectional view showing the stacked maskfilm used in the embodiment.

As shown in FIG. 20, the embodiment is different in the configuration ofthe stacked mask film for forming the memory holes compared to thefourth embodiment described above.

As shown in FIG. 20, in the embodiment, the boron carbide film 81consisting primarily of boron carbide (BC) is formed on the stacked body15 (see FIG. 1). Then, a carbon-boron-containing tungsten film 92consisting primarily of tungsten and including boron (B) and carbon (C)is formed on the boron carbide film 81. The method of forming thecarbon-boron-containing tungsten film 92 is substantially the same asthe method of forming the carbon-boron-containing tungsten film 71 inthe third embodiment. The method of forming the boron carbide film 81 issubstantially the same as in the fourth embodiment. Thecarbon-boron-containing tungsten film 92 is formed to be thicker thanthe boron carbide film 81.

Thereafter, the boron carbide films 81 and the carbon-boron-containingtungsten films 92 are alternately formed to form a stacked film 93. Itshould be noted that in the boron carbide film 81, tungsten mayinevitably diffuse from the carbon-boron-containing tungsten film 02 insome cases, but the tungsten concentration in the boron carbide film 81is lower than the tungsten concentration in the carbon-boron-containingtungsten film 92. Further, the total concentration of carbon and boronin the carbon-boron-containing tungsten film 92 is lower than the totalconcentration of carbon and boron in the boron carbide film 81. Then, bypatterning the stacked film 93, the stacked mask film 93 m is formed.

Except the points described above, the manufacturing method,configurations, and advantages of the semiconductor device in theembodiment are substantially the same as in the fourth embodimentdescribed above.

It should be noted that the second through fifth embodiments can also beput into practice in combination with the first modified example and thesecond modified example of the first embodiment. Specifically, in thesecond through fifth embodiments, it is also possible to provide theliner film 20 as in the first modified example (see FIG. 15) of thefirst embodiment. Further, in the second through fifth embodiments, itis also possible to form a part of the block insulating film 39 from thememory hole 26 side as in the second modified example (see FIG. 16) ofthe first embodiment. Further, also in the second through fifthembodiments, similarly to the first embodiment, the metal constitutingthe metal films and the stress-decoupling films is not limited totungsten, but can also be, for example, molybdenum, tantalum, cobalt, ortitanium.

Further, although in each of the embodiments described above, there isdescribed the example of manufacturing the stacked-type nonvolatilesemiconductor memory device as the semiconductor device, this example isnot a limitation, and each of the embodiments can be applied to aprocess including processing high in aspect ratio.

According to the embodiments described hereinabove, it is possible torealize the method of manufacturing the semiconductor device easy tomanufacture.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the invention.

What is claimed is:
 1. A method of manufacturing a semiconductor device,comprising: forming a first film including a first metal above aprocessing target member; forming a second film including two or moretypes of element out of a second metal, carbon, and boron above thefirst film; forming a third film including the first metal above thesecond film; forming a mask film by providing an opening part to astacked film including the first film, the second film and the thirdfilm; and processing the processing target member by performing etchingusing the mask film as a mask.
 2. The method according to claim 1,further comprising: forming a fourth film including two or more types ofelement out of the second metal, carbon, and boron above the processingtarget member, the first film being formed above the fourth film, andthe stacked film including the fourth film.
 3. The method according toclaim 2, wherein a silicon oxide is exposed on an upper surface of theprocessing target member.
 4. The method according to claim 1, furthercomprising: forming a fourth film including the first metal and nitrogenon the processing target member, the first film being formed on thefourth film, and the opening part being provided also to the fourth filmin the forming of the mask film.
 5. The method according to claim 1,wherein the forming of the second film and the forming of the third filmare alternately performed.
 6. The method according to claim 5, whereinthe third film is formed thicker than the second film.
 7. The methodaccording to claim 1, wherein the second metal and the first metal arethe same in type.
 8. The method according to claim 1, wherein the firstmetal and the second metal are each selected from a group consisting oftungsten, molybdenum, tantalum, cobalt, and titanium.
 9. The methodaccording to claim 1, wherein the second film includes at least one ofcarbon and boron as the element, and the second film includes the secondmetal as the element.
 10. The method according to claim 9, wherein thesecond film includes the second metal and carbon, the second metal andthe first metal are the same in type, and the first film and the thirdfilm are lower in carbon concentration than the second film.
 11. Themethod according to claim 9, wherein the second film includes the secondmetal and boron, the second metal and the first metal are the same intype, and the first film and the third film are lower in boronconcentration than the second film.
 12. The method according to claim 9,wherein the second film includes the second metal, carbon, and boron,the second metal and the first metal are the same in type, and the firstfilm and the third film are lower in total concentration of carbon andboron than the second film.
 13. The method according to claim 1, whereinthe second film includes carbon and boron as the element, and the firstfilm and the third film are lower in total concentration of carbon andboron than the second film.
 14. The method according to claim 13,wherein the first film and the third film further include carbon andboron.
 15. The method according to claim 1, further comprising: removingthe mask film after the processing of the processing target member. 16.The method according to claim 1, wherein the second film is weaker incompressive stress than the third film.
 17. The method according toclaim 1, wherein tensile stress is caused in the second film, andcompressive stress is caused in the third film.
 18. The method accordingto claim 1, wherein insulating films and sacrifice films are alternatelystacked above a substrate in the processing target member, theprocessing of the processing target member includes forming a holepenetrating the insulating films and the sacrifice films and reachingthe substrate, and the method further comprising: forming a chargestorage film on an inner surface of the hole; forming a tunnelinsulating film on a side surface of the charge storage film; forming asemiconductor pillar on a side surface of the tunnel insulating film;forming an opening part penetrating the insulating films and thesacrifice films after the forming of the semiconductor pillar; removingthe sacrifice films by performing etching via the opening part; andforming electrode films in spaces from which the sacrifice films havebeen removed.
 19. A method of manufacturing a semiconductor device,comprising: forming a stacked body by alternately forming first layersand second layers above a substrate; forming a first film including afirst metal above the stacked body; forming a second film above thefirst film, the second film including at least one of carbon and boron,and the second film including the first metal; forming a third filmincluding the first metal above the second film; forming a mask film byproviding an opening part to a stacked film including the first film,the second film and the third film; forming a hole penetrating the firstlayers and the second layers and reaching the substrate by performingetching using the mask film as a mask; forming a charge storage film onan inner surface of the hole; forming a tunnel insulating film on a sidesurface of the charge storage film; and forming a semiconductor pillaron a side surface of the tunnel insulating film, the first film and thethird film being lower in total concentration of carbon and boron thanthe second film.
 20. The method according to claim 19, furthercomprising: removing the mask film after the forming of a hole.